Short read: Why is only 10 percent of the population left-handed?

Ultrasound scans show that we become left or right handed when we are in our mother’s womb i.e. the foetus starts moving either its right hand or its left hand long before birth. Whilst there is a lot randomness in this early embryonic development, the video uses research conducted by the researchers at the Max Planck Institute for Psycholinguistics on 350K people to show that left-handedness is linked to a specific gene called TUB4B.

TUB4B is also linked to other rare genetic disorders which are more common in left handers than right handers. These disorders are 2.7x more likely to appear in lefties rather than righties. “That suggests that the TUB4B gene codes for a protein than is linked to the asymmetrical development of the brain…This asymmetry is important in the brain for motor skills and for ability to use language”